In the field of photographic art, it is known to use polymers having quaternary ammonium salts in side chains as a mordant described in U.S. Pat. Nos. 3,709,690, 3,958,995, 3,898,088, etc. However, such polymers have the defect that, though they show good mordanting properties for dyes, they are poor in their ability to retain mordanted dyes in a stable form. That is, a photographic system containing a dye image mordanted with this type mordant has the defect that the mordanted dye image is liable to undergo chemical change or decomposition when irradiated with light emitted from a fluorescent lamp, sunlight, or the like.
Polymeric mordants are usually coated on a support or other coated layer using a hydrophilic colloid such as gelatin as a binder. However, in comparison with coated layers formed of hydrophilic colloid alone, coated layers containing this type polymeric mordant and hydrophilic colloid show considerably different dynamic properties. That is, a layer formed of a mixture of polymeric mordant and, for example, gelatin, has been found to undergo serious reduction in tensile strength and elongation at break, in comparison with a layer formed of gelatin alone, and, as a result, is relatively brittle. This deterioration of the coated layer in terms of brittleness causes cracks due to thermal and dynamic strain generated in a layer-coating step or a layer-drying step and, therefore, seriously limits the production conditions such as coating conditions and drying conditions.
In addition, it has been found that, when thermal or dynamic strain is generated during handling of the dye-fixing element, it undergoes layer breakage (cracking) of the mordant layer contained therein.
When the aforesaid image-forming process is conducted using the thus cracked dye-fixing element, uneven development and/or uneven dye transfer result, or false cuts appear in the image; thus the image quality is seriously deteriorated.